Sorry for replying so late, my real job kept me busy.
So, yes, having an active high pass filter is a very good thing. About 3 out of 4 a’goners who apply a high pass filter _and_ raise the crossover point to ~ 80 to 100 Hz report greatly improved imaging and clarity.
The mistake I see many audiophiles make is they go by speaker spec and how much they spent on their main speakers. "I bought these enormous floor standers and paid $7,000 for them so I want to get every single Hz out of them that i can" goes the thought. They then throw a subwoofer into the mix, and set the low pass filter ~ 40 Hz and achieve extremely mediocre results.
Using a high pass filter (i.e. crossover) lets you minimize distortion, excursion and power sent to your main speakers which often achieves exceptional improvements in clarity especially with 2-way speakers. The physics is relatively simple. If you add a sub the main amplifier and speakers still get 100% of the frequency range of the music. A high pass filter reduces that so that the bass, which is where most of the cone movement and amplifier power is spent, is greatly reduced before your amplifier sees it.
Also consider potentially sealing the ports on the back. This may make it easier to integrate with the subwoofer and reduce distortion. A clean tight sock stuffed in the back will do, won’t harm anything and is immediately reversible.
Two other tips. Use the AM Acoustics room mode simulator to help you place all of your speakers and your listening location. Use your own measurements instead of speaker specs or dial settings. Absolutely nothing about a speaker’s -3 dB point in the low end matters once it’s in a room.
